Mechanical Test for Anisotropy; Failure of Aluminoborosilicate Glass Fibers Under Combined Loadings of Tension and Torsion

Abstract

The failure behavior of aluminoborosilicate glass fibers in pure tension, pure torsion, and under combined loadings of tension and torsion was investigated. It was established that the glass fibers failed in accordance with the predictions of the Weibull statistical theory of failure and the maximum principal stress theory of failure. Therefore, it could be concluded that the fibers were isotropic. A general procedure was developed for detecting structural anisotropy by experimentally evaluating the average torsional and tensile strengths of a material and comparing their ratio with the ratio predicted when the experimental data are analyzed in terms of the Weibull theory.